Diamond was a surprise breakout player in 2012 and led Minnesota's rotation, but his low velocity and strikeout rate caught up with him in 2013 and he struggled – putting his spot in the 2014 rotation in jeopardy. Diamond doesn't have great velocity (88.6 mph fastball), but he's had success in the minors with a low walk rate and by keeping the ball on the ground. He had a delayed start to his 2013 season after offseason surgery to remove bone chips in his throwing elbow, but it didn't appear to impact him as initially it looked like he would repeat his 2012 success. He had a 3.03 ERA with a 15:3 K:BB ratio in 29.2 innings through six starts. However, he struggled with a 6.13 ERA and 33:37 K:BB ratio over 101.1 innings the rest of the season. His walk rate increased to 2.5 BB/9 and his groundball rate fell to 46.9%. Both figures are decent, but Diamond's poor velocity needs outstanding control considering his strikeout rate fell to just 3.6 K/9. Diamond will contend for a spot in the rotation this spring, but it's possible he's reached his peak and will just add depth at Triple-A.

2013

Diamond was about the only thing to go right for the Minnesota rotation last season as the former Rule 5 pick had a breakout year and won 12 games with a 3.54 ERA. Diamond has mediocre velocity (89.3 mph average fastball) which results in low strikeout rates (4.7 K/9), but he is good at inducing groundballs (53.4 percent of batted balls) and has sterling control. With a low strikeout rate, he will need to keep the ball on the ground and continue to avoid free passes. He had the lowest walk rate of his career last season, and needs to keep that up to repeat his success. He enters 2013 at the top of Minnesota's rotation.

2012

Even though he struggled at Triple-A last season, Diamond was called up to the majors and had seven starts late in the season when the Minnesota rotation was ravaged with injuries. Even though he has mediocre velocity, he'd been quietly productive in Atlanta's organization, with strong groundball rates (1.77 GB/FB rate in 2010). The Twins acquired him in a trade and he began the season in the Triple-A Rochester rotation, but he had a 5.56 ERA with a lackluster 6.59 K/9IP. He did have good control and a 1.31 GB/FB. He predictably struggled in the majors, with a 5.08 ERA and poor 19:17 K:BB ratio in 39 innings. He'll enter spring training with a shot to win a job in the bullpen, but he more likely adds depth at Triple-A all season. If he gets a chance, there's little in his skill set to entice fantasy owners.

2011

Diamond hasn't had a high profile because he has mediocre velocity, but he's been quietly productive with strong ground-ball rates (1.77 GO/AO rate in 2010). A Rule 5 pick from Atlanta, the Twins later acquired his rights in a trade and he'll begin the season at Triple-A. He could be a factor in middle relief in the majors this summer.